Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P02794 (ferritin)
 17,525 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Measurement of the incorporation of iron into liver cells and liver ferritin of the rat revealed that both incorporated less iron under tumor-bearing condition than in the normal state.
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PMID:Iron incorporation into liver cells and ferritin of tumor-bearing rats. 19 25

Serum ferritin (SF) is elevated in adults with malignancies, chronic inflammatory disease, liver disease and iron overload. The purpose of this study was to determine whether the concentration of SF in children with a variety of malignancies correlated with the activity of their disease. Patients with acute lymphoblastic leukaemia (ALL) at initial diagnosis (n = 11) and relapse (n = 15) had a mean SF of 238 and 338 ng/ml, respectively, compared to the normal mean of 31 ng/ml and range of 7 to 140 ng/ml in children. In 30 patients with ALL in remission the mean SF was 109 ng/ml, less than the values in patients with active disease and greater than the normal mean (P less than 0.001). The concentration of SF was also increased in a group of 77 patients with a variety of solid tumors. The 28 cases with active disease had a mean SF of 242 ng/ml, significantly higher (P less than 0.001) that the value of 84 ng/ml in 49 patients with no evidence of residual tumor. The differences in SF concentration did reflect the activity of disease in the groups as a whole but it remains uncertain whether the assay will prove useful in following the response to treatment of patients with certain types of tumor.
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PMID:Elevated serum ferritin in children with malignancies. 19 90

The mechanism of tumor localization of gallium-67 (67Ga) is not known with certainty, although much information has been derived regarding the biodistribution and subcellular fate of 67Ga in a variety of tumors and other tissues from experimental animals. After intravenous administration, 67Ga is bound to transferrin in the blood, and distributed to liver, lacrimal glands, salivary glands, and soft tissue tumors. Within the cells of the liver and tumors, gallium is found in lysosomes, and rough endoplasmic reticulum. Within these organelles, 67Ga is bound to a variety of macromolecules, including transferrin, ferritin, and a 45,000 molecular weight glycoprotein. Recent studies of tumor cells growing in tissue culture suggest an important role for transferrin in 67Ga tumor uptake. This uptake is mediated by a transferrin specific cellular receptor.
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PMID:Mechanisms of localization of gallium-67 in tumors. 21 49

Ferritin was purified from normal, fetal, and malignant liver tissue. Ferritin purified from hepatoma tissue migrated slightly faster than normal human liver ferritin in polyacrylamide gel electrophoresis. Hepatoma and fetal liver ferritin contained an acidic components in gel and liquid isoelectric focusing not found in normal liver ferritin. We have called it a carcinofetal isoferritin. The subunit compositions of ferritins purified from human liver cell carcinoma and normal liver were then compared. Both ferritin consisted of a subunit species with an identical molecular weight of approximately 18,500. A single subunit of similar molecular weight was also demonstrable after dissociation of 8 M urea and by gel filtration in urea. Two subunits were demonstrable in normal liver ferritin by means of acrylamide electrophoresis in 8 M urea in acid pH. The same two subunits were also demonstrable in ferritin isolated from human liver cell carcinoma. However, a third subunit, intermediate in charge between the two normal liver subunits, was demonstrable in different amounts in ferritins from two hepatomas. Ferritins from normal and malignant livers were immunologically indistinguishable. The tumor-specific acidic isoferritin was isolated and antisera were prepared. The isolated acidic isoferritin was found to be immunologically identical to normal liver isoferritins. It is concluded that the multiple isoferritins of the human liver ferritin consist of two subunits, which are identical in molecular weight but which differ in net charge. Ferritin, isolated from two human liver carcinoma tissues, was composed of the same two subunits and a third unique subunit. Different amounts of these subunits may account for the several normal isoferritins and a unique tumor-specific acid isoferritin found in hepatoma.
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PMID:Characterization and subunit analysis of ferritin isolated from normal and malignant human liver. 23 22

Horseradish peroxidase (HRP) uptake was used to measure fluid-phase pinocytosis in monolayers of human epithelioid carcinoma cells (A-431). Histochemistry confirmed that cell-associated HRP was restricted to intracellular vesicles. Biochemical methods showed that HRP uptake in control cultures was directly proportional to the duration of exposure. The addition of low concentrations of epidermal growth factor (EGF) to the incubation media produced a 10-fold increase in the initial rate of pinocytosis. The EGF effect was rapid (within 30 s) but transient; the rate of pinocytosis returned to control levels within 15 min. Metabolic inhibitors reduced the EGF-stimulated rate of pinocytosis by greater than 90%. A conjugate of EGF and ferritin (F:EGF) was used to simultaneously compare the intracellular locations of EGF and HRP. Much of F:EGF was internalized in approximately 100-nm vesicles, while most of the HRP was located in much larger vesicles (range 0.1--1.2 micrometer) which also contained F:EGF. The tumor-promoter 12-0-tetradecanoyl-phorbol-13-acetate, which shares several biological activities with EGF, was also effective in stimulating an increase in the rate of pinocytosis.
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PMID:Rapid stimulation of pinocytosis in human carcinoma cells A-431 by epidermal growth factor. 31 44

Statistical procedures were utilized to evaluate the concentration dependence of labeling by ferritin-conjugated lectins on four different rat cells: hepatocytes, normal thymocytes, Friend virus-induced rat tumor cells and feline sarcoma virus-induced rat sarcoma cells. Labeling by ferritin conjugates of concanavalin A, wheat germ agglutinin and Ricinus communis agglutinins I and II was quantitated by counting the number of ferritin granules on 600 Angstrom membrane segments. Relationships between the arithmetic means and variances for sample populations from each cell and ferritin-lectin combination were used to define four types of topographical distributions: uniform/ordered, uniform/random, random and clustered. It was found that the distribution and/or density of surface-bound lectin was concentration-dependent for all four ferritin-lectins. The nature of this dependency was complex and varied with both lectin and cell type.
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PMID:A statistical evaluation of the binding of ferritin-conjugated lectins to the surface of rat cells. Topographical variations as a function of lectin concentration and cell type. 31 39

Although our knowledge of immunologic processes in breast cancer is still inadequate, many preliminary studies described here may yield valuable information after long-term patient follow-up. At present, there is no specific tumor marker diagnostic of breast cancer, but markers such as CEA, ferritin, immune complexes, and specially estrogen receptors have strong potential as prognostic indicators. As a group, breast cancer patients, as do those with other malignancies, demonstrate reduced immunologic capacity, therefore assays of nonspecific immune function may not be relevant. Assays of "specific" reactivity to breast tumor antigens, however, warrant further investigation as clinical tools. Application of immunotherapy to breast cancer is relatively recent and few trials have more than preliminary data. Determination of estrogen receptors should be included in future clinical immunotherapy protocols so that true evaluation of immunologic responses may benefit, hopefully, from our awareness of the endocrine milieu.
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PMID:Immunology, tumor markers, and breast cancer. 35 94

We examined the binding of soluble immune complexes in sera from patients with Hodgkin's disease to established tissue cultures derived from the tumor. Circulating immune complex levels were determined by the Raji cell assay, and the reaction of serum with cultured cells was examined with a radioimmune assay and by immunoferritin electron microscopy. Serum with elevated immune complexes was found to react with cells of Hodgkin's disease monolayers when tested with radioiodine-labeled antisera against human IgG heavy and light chains and the complement 3 (C3) component. When examined with the electron microscope, monolayers incubated with Hodgkin's disease serum containing immune complex and labeled with ferritin-conjugated antiserum to C3 contained surface-bound ferritin particles with a uniform but discontinuous pattern. Absorption of Hodgkin's disease serum with monolayer cells reduced immune complexes and decreased reactivity of the sample with cultured cells by radioimmune assay. Sera of patients with other disorders and aggregated gamma-globulin with complement, despite markedly elevated immune complex levels, did not react positively with monolayers derived from Hodgkin's disease tumors, and none of the sera reacted with normal cultured spleen. The approximate size of serum components reacting with Hodgkin's disease monolayers was estimated by sucrose density gradient centrifugation. Sedimentation fractions in the 19S region reacted with monolayer cells when tested with 125I-labeled antisera to both IgG and C3 and contained immunoglobulin-complement complexes by gel diffusion and immunoabsorption. A component sedimenting at 7-9S contained immunoglobulin not complexed with complement; this component reacted with monolayer cells when tested with anti-IgG antiserum but did not react when tested with antibody to C3. The reaction of Hodgkin's disease monolayers with serum containing immune complexes differed from that of two suspension culture lines composed of cells with surface complement and IgG Fc receptors. Inasmuch as cells of our long-term Hodgkin's disease monolayers do not contain these surface receptors, possibly the antibody component of the immune complex reacts with antigens on the surface of cultured cells.
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PMID:Reaction of immune complexes with Hodgkin's disease tissue cultures: radioimmune assay and immunoferritin electron microscopy. 37 54

This study demonstrates the feasibility of using scanning electron microscopy for the identification and mapping of two or more antigens on cell surfaces. Three types of cells: human type B red cells, tumor cells and their associated virus, and guinea pig hepatocarcinoma cells were immunolabeled with ferritin or gold conjugated to IgG fractions of antigen-specific antisera. Gold particles, 300-500 A in diameter, were conjugated to an IgG fraction either directly or indirectly using Staphylococcal protein A. Gold particles of this size can be distinguished from ferritin label using a high resolution scanning microscope. Correlative light, transmission electron microscopy, and scanning electron microscopy studies, as well as x-ray diffraction analysis and the study of stereo micrographs, were performed to visualize the simultaneous immunolabeling by ferritin and gold of two antigens on the guinea pig hepatocarcinoma cell.
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PMID:Scanning immunoelectron microscopy for the identification and mapping of two or more antigens on cell surfaces. 39 23

To evaluate the ultrastructural distribution of transferrin on the surface of L1210 ascites tumor cells, we used ferrocyanide to stain ferric iron (Prussian blue reaction) in transferrin, as well as in ferritin conjugated to antibody that was immunologically attached to the transferrin. Small deposits averaging 5 nm in diameter identified transferrin iron, whereas large cuboidal deposits averaging 50 nm in diameter stained ferritin conjugated-antibody that was bound to both transferrin and apotransferrin on the cell surface. The ability of transferrin to deliver iron to ascites tumor cells was confirmed by kinetic studies of transferrin labeled with 59Fe and 125I. These preliminary results are consistent with release of transferrin iron at the cell surface and demonstrate additional uses for ferrocyanide in ultrastructural cytochemical techniques.
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PMID:Ferrocyanide staining of transferrin and ferritin-conjugated antibody to transferrin. 44 60


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